1. Field of the Invention
A wide variety of ways have been developed for determining minute quantities of various organic compounds. A number of methods which can be used for the determination of organic compounds depend on the availability of a receptor which recognizes a particular compound or class of compounds. The most common type of receptor is the antibody which is able to strongly bind to a particular spatial conformation and polar or non-polar distribution.
In order to prepare the antibodies for compounds which are not antigenic, the non-antigenic compound is normally bonded to an antigenic material, particularly a protein. With most compounds, it is found necessary to modify the compound of interest to bond to the antigen.
In addition, in some of the immunoassays, it is necessary to bond the compound to a detector molecule. The link that is chosen for bonding to the antigen and to the detector molecule must allow not only for satisfactory bonding to the various molecules, but also must provide an antibody which recognizes the compound when it is bound to the detector molecule.
In addition, the linking group must not significantly change the polar characteristics of the compound to be assayed nor detrimentally affect the molecules to which the compound is bonded. Depending on the particular material to which the compound is to be bonded, the linking group should permit a sufficient number of the desired compound to be bonded to the antigen or detector molecule. Additional considerations include synthetic simplicity, chemical stability, the effect of the bonding functionality on the material to which it is bonded, and the particular site on the material, for example, a protein, to which the compound will be bonded.
2. Description of the Prior Art
An immunoassay technique employing a stable free radical detector, entitled FRAT.sup.R, supplied by Syva Corporation, is described in U.S. Pat. No. 3,690,834. Another immunoassay technique using enzymes as a detector and commercially available as EMIT.sup.TM, supplied by Syva Corporation, is found in copending application, Ser. No. 143,609 filed May 14, 1971. Radioimmunoassay is described in a number of texts for example Kirkham, et al, Radioimmunoassay Methods, Churchill, Livingston, London, 1971. A description of a number of derivatives of cocaine and ecgonine may be found in Pelletier, Chemistry of the Alkaloids, Van Nostrand-Reinholt, New York 1970. U.S. Pat. No. 3,498,989 also discloses a number of cocaine derivatives. Odell, Competitive Protein Binding, Blackwell Scientific Publications, Oxford 1971, Chapter II, page 25, describes various methods of conjugating haptens to antigens.